EP0876907A2 - Photocatalyst sheet - Google Patents
Photocatalyst sheet Download PDFInfo
- Publication number
- EP0876907A2 EP0876907A2 EP97928504A EP97928504A EP0876907A2 EP 0876907 A2 EP0876907 A2 EP 0876907A2 EP 97928504 A EP97928504 A EP 97928504A EP 97928504 A EP97928504 A EP 97928504A EP 0876907 A2 EP0876907 A2 EP 0876907A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- photocatalytic
- base
- protective layer
- sheet according
- fibers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 239000011941 photocatalyst Substances 0.000 title 1
- 230000001699 photocatalysis Effects 0.000 claims abstract description 118
- 239000000835 fiber Substances 0.000 claims abstract description 61
- 239000004065 semiconductor Substances 0.000 claims abstract description 56
- 239000010410 layer Substances 0.000 claims abstract description 39
- 239000011241 protective layer Substances 0.000 claims abstract description 24
- 239000004745 nonwoven fabric Substances 0.000 claims abstract description 17
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 16
- 239000002759 woven fabric Substances 0.000 claims abstract description 14
- 239000004744 fabric Substances 0.000 claims abstract description 12
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 56
- 239000000463 material Substances 0.000 claims description 50
- 239000002245 particle Substances 0.000 claims description 37
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 29
- 239000000057 synthetic resin Substances 0.000 claims description 16
- 229920003002 synthetic resin Polymers 0.000 claims description 16
- 238000001228 spectrum Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 230000002269 spontaneous effect Effects 0.000 claims description 5
- 238000000862 absorption spectrum Methods 0.000 claims description 2
- 230000031700 light absorption Effects 0.000 claims description 2
- 230000005855 radiation Effects 0.000 abstract description 10
- 238000005406 washing Methods 0.000 abstract description 3
- 230000006866 deterioration Effects 0.000 description 23
- 238000004040 coloring Methods 0.000 description 13
- 229920000728 polyester Polymers 0.000 description 11
- 239000012467 final product Substances 0.000 description 9
- -1 polypropylene Polymers 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 238000010521 absorption reaction Methods 0.000 description 7
- 238000000354 decomposition reaction Methods 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 230000033116 oxidation-reduction process Effects 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 229920000742 Cotton Polymers 0.000 description 6
- 239000002253 acid Substances 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 230000000717 retained effect Effects 0.000 description 6
- 229920000297 Rayon Polymers 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000007774 longterm Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000002964 rayon Substances 0.000 description 5
- 230000001954 sterilising effect Effects 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 4
- 239000012855 volatile organic compound Substances 0.000 description 4
- 239000004743 Polypropylene Substances 0.000 description 3
- 229910010252 TiO3 Inorganic materials 0.000 description 3
- 230000005856 abnormality Effects 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- 238000000295 emission spectrum Methods 0.000 description 3
- 239000003365 glass fiber Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- 239000008399 tap water Substances 0.000 description 3
- 235000020679 tap water Nutrition 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 2
- 229920000914 Metallic fiber Polymers 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000005084 Strontium aluminate Substances 0.000 description 2
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 2
- 229920005822 acrylic binder Polymers 0.000 description 2
- WMWLMWRWZQELOS-UHFFFAOYSA-N bismuth(iii) oxide Chemical compound O=[Bi]O[Bi]=O WMWLMWRWZQELOS-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000001877 deodorizing effect Effects 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 239000005329 float glass Substances 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 2
- 239000002649 leather substitute Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N nickel(II) oxide Inorganic materials [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- 235000019645 odor Nutrition 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000007146 photocatalysis Methods 0.000 description 2
- 238000004659 sterilization and disinfection Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 229920002994 synthetic fiber Polymers 0.000 description 2
- 239000012209 synthetic fiber Substances 0.000 description 2
- 244000025254 Cannabis sativa Species 0.000 description 1
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 description 1
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- 229910016003 MoS3 Inorganic materials 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 101100258086 Postia placenta (strain ATCC 44394 / Madison 698-R) STS-01 gene Proteins 0.000 description 1
- 229910052773 Promethium Inorganic materials 0.000 description 1
- 229910003669 SrAl2O4 Inorganic materials 0.000 description 1
- 229910002370 SrTiO3 Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- CXKCTMHTOKXKQT-UHFFFAOYSA-N cadmium oxide Inorganic materials [Cd]=O CXKCTMHTOKXKQT-UHFFFAOYSA-N 0.000 description 1
- 229910052980 cadmium sulfide Inorganic materials 0.000 description 1
- 235000009120 camo Nutrition 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 235000005607 chanvre indien Nutrition 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000000110 cooling liquid Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- BERDEBHAJNAUOM-UHFFFAOYSA-N copper(I) oxide Inorganic materials [Cu]O[Cu] BERDEBHAJNAUOM-UHFFFAOYSA-N 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- KRFJLUBVMFXRPN-UHFFFAOYSA-N cuprous oxide Chemical compound [O-2].[Cu+].[Cu+] KRFJLUBVMFXRPN-UHFFFAOYSA-N 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000012447 hatching Effects 0.000 description 1
- 239000011487 hemp Substances 0.000 description 1
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 1
- 230000000415 inactivating effect Effects 0.000 description 1
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 description 1
- 208000015181 infectious disease Diseases 0.000 description 1
- 239000012784 inorganic fiber Substances 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 239000001023 inorganic pigment Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000007721 medicinal effect Effects 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 229910052961 molybdenite Inorganic materials 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- TVWWSIKTCILRBF-UHFFFAOYSA-N molybdenum trisulfide Chemical compound S=[Mo](=S)=S TVWWSIKTCILRBF-UHFFFAOYSA-N 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- VQMWBBYLQSCNPO-UHFFFAOYSA-N promethium atom Chemical compound [Pm] VQMWBBYLQSCNPO-UHFFFAOYSA-N 0.000 description 1
- 230000005258 radioactive decay Effects 0.000 description 1
- 229910052705 radium Inorganic materials 0.000 description 1
- HCWPIIXVSYCSAN-UHFFFAOYSA-N radium atom Chemical compound [Ra] HCWPIIXVSYCSAN-UHFFFAOYSA-N 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- FNWBQFMGIFLWII-UHFFFAOYSA-N strontium aluminate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Al+3].[Al+3].[Sr+2].[Sr+2] FNWBQFMGIFLWII-UHFFFAOYSA-N 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 150000003852 triazoles Chemical class 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten(VI) oxide Inorganic materials O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 238000009941 weaving Methods 0.000 description 1
- 239000012463 white pigment Substances 0.000 description 1
- 210000002268 wool Anatomy 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N zinc oxide Inorganic materials [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
- B01J35/39—Photocatalytic properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/80—Type of catalytic reaction
- B01D2255/802—Photocatalytic
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2927—Rod, strand, filament or fiber including structurally defined particulate matter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2933—Coated or with bond, impregnation or core
- Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
- Y10T428/2942—Plural coatings
- Y10T428/2949—Glass, ceramic or metal oxide in coating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2933—Coated or with bond, impregnation or core
- Y10T428/2964—Artificial fiber or filament
- Y10T428/2967—Synthetic resin or polymer
Definitions
- TiO 2 titanium oxide
- optical semiconductors Since electrons on their surface are made movable relatively freely when they are excited by ultraviolet rays.
- the optical semiconductor has a photocatalytic function of oxidizing or deoxidizing a substance in contact with a surface of the semiconductor by the electrons which are rendered freely movable by the excitation.
- the photocatalytic function is utilized in a daily life to attain an effect of deodorization or sterilization.
- the photocatalytic function is given to materials of interiors including ceilings and walls, or the photocatalytic semiconductor is retained in curtains which are often exposed to ultraviolet radiation of the sunlight.
- the air which rises to circulate in the room as being heated by the sunlight comes into contact with sheets of these materials, so that odors in the room and volatile organic compounds (VOC) contained in adhesives in backings of the interior materials are effectively removed.
- VOC volatile organic compounds
- the woven fabrics for the interior materials and the curtains, as well as filters in various devices, medical gauze, moistened tissue and nonwoven fabrics such as artificial leather have a large number of gaps between their fibers and thus are multi-surface objects, and hygienic, medical or deodorizing effect can advantageously be obtained by imparting the photocatalytic function to these objects.
- the photocatalytic function is originally a function of decomposing the polymeric organic compounds by the oxidization/deoxidization action of the photocatalytic semiconductor which is excited by irradiation of ultraviolet rays. Therefore, no problem arises if the base retaining the photocatalytic semiconductor is made of an inorganic material such as metallic fibers or glass fibers, but in the case where the base is made of fibers of polymeric organic compound such as natural fibers or synthetic resin fibers, the base itself is decomposed and deteriorated with lapse of time (deterioration by photocatalysis).
- Japanese Laid-Open Patent Publication No. 7-316342 discloses that synthetic resin containing particles of photocatalytic semiconductor is formed into a sheet for wall materials, floor materials, and various bags. However, when the photocatalytic semiconductor particles are thus kneaded into the base, the photocatalytic function cannot be fully achieved. Also, the technique disclosed in this publication cannot be applied to fabric made of natural fibers which cannot be kneaded.
- Japanese Laid-Open Patent Publication No. 8-1010 discloses an adhesive sheet having a layer of fine particles of oxide semiconductor on one surface thereof, an adhesive layer as an intermediate layer, and a separating layer on the other surface thereof. This sheet is intended to use at locations where it is difficult to fix photocatalytic semiconductor particles, such as walls or ceilings, and also cannot be applied to soil material such as gauze.
- An object of the present invention is providing a photocatalytic sheet which has a base, made of polymeric organic compound and retaining photocatalytic semiconductor, that is not decomposed by a photocatalytic function, and thus can withstand long-term use.
- the object includes providing a photocatalytic sheet which hardly loses the photocatalytic function even if washed, and is capable of providing the photocatalytic function even in an environment without sufficient ultraviolet radiation from outside.
- the base includes a fiber, a filament, a yarn made of fibers or filaments, a ribbon, a knitted fabric, a woven fabric, a nonwoven fabric, and a film made of synthetic resin.
- the base protective layer may comprise noncrystalline titanium peroxide particles or titanium oxide particles inactivated with respect to photocatalytic function.
- the photocatalytic semiconductor layer may comprise constituted by titanium oxide particles.
- the base may retain a spontaneous emission-type ultraviolet radiating material or a light storage-type ultraviolet radiating material.
- the compositions of the ultraviolet radiating material and the photocatalytic semiconductor layer are adjusted so that a peak region of wavelength spectrum of light radiated from the ultraviolet radiating material is shifted from a peak region of wavelength spectrum of light to be absorbed by the polymeric organic compound, and overlaps at least in part with a peak region of light absorption spectrum of the photocatalytic semiconductor layer.
- a photocatalytic sheet according to the present invention may take the form of a knitted fabric, a woven fabric, a nonwoven fabric, or a film.
- the material of the sheet may be natural fibers such as hemp, cotton and wool, and also synthetic fibers (including filaments) or synthetic resin of polyester, rayon, nylon, polypropylene, vinyl, acetate, acrylic, etc.
- the sheet except the film is formed through the steps of fibers, spun yarns, twisted yarns, or ribbons.
- a base protective layer is constituted by a layer of noncrystalline titanium peroxide particles formed using an aqueous solution of titanium peroxide, a peroxotitanic acid, a peroxotitanic acid containing an oxide of metal other than titanium, etc., or by a layer of titanium oxide particles inactivated in respect of photocatalytic function.
- the layer obtained in this manner has no photocatalytic function and thus does not decompose the base.
- the layer of noncrystalline titanium peroxide particles can be formed on the surface of the base in the following manner, for example.
- the surface of the base may alternatively be coated with an aqueous solution of peroxotitanic acid by, for example, dipping as in the aforementioned manner, dried and then heated for fixing at a temperature of 200°C or less.
- the resultant noncrystalline titanium peroxide particles show a property similar to that of titanium oxide of anatase type and have a photocatalytic function.
- a raw resin for forming fibers as the base may be ejected from a nozzle into an aqueous solution of peroxotitanic acid so that a thin film of noncrystalline titanium peroxide particles may be formed on the surface of each fiber.
- the fibers are dried and then heated so as to fix the titanium peroxide at a temperature of 200°C or less. The fixing may be performed after spinning, after twisting, or after weaving.
- the layer of titanium oxide inactivated in respect of the photocatalytic function may be formed on the surface of the base in the following manner, for example.
- An ionic surface-active agent is mixed in a sol of titanium oxide of anatase type such that the surface-active agent accounts for 1 wt% or more with respect to the concentration of the titanium oxide (TiO 2 ) in the sol, thereby inactivating the photocatalytic function of the titanium oxide, and then the base is sprayed with, dipped into, or applied with the sol. Subsequently, the base is dried and then heated for fixing the titanium oxide.
- a photocatalytic semiconductor layer is formed on the surface of the base treated in this manner, and in this case, even if the photocatalytic semiconductor is excited upon exposure to ultraviolet radiation, electrons moving toward the surface of the base combine with ions of the ionic surface-active agent contained in the base protective layer, thus preventing oxidation-reduction of the surface of the base. Consequently, the base is not affected by the photocatalytic function and thus can be protected.
- the base on which the photocatalytic semiconductor is to be retained is not limited to the form of knitted fabric, woven fabric, nonwoven fabric or film, but may be of various forms obtained in respective steps of the sheet production process, such as fibers, spun yarns, twisted yarns, or ribbons.
- Particles of photocatalytic semiconductor may be affixed at early stages of the process to fibers or yarns, for example, on condition that no difficulty arises in performing the treatment, in which case the photocatalytic semiconductor is firmly fixed to the resultant sheet and the photocatalytic function can be retained even if the sheet is washed several times.
- the base retaining photocatalytic semiconductor for imparting the photocatalytic function to the sheet one or some of the forms including fiber, filament, yarn, ribbon, knitted fabric, woven fabric, nonwoven fabric and film may be selected depending on the purpose.
- the layer of noncrystalline titanium peroxide particles or the layer of inactivated titanium oxide needs to be formed on natural fibers or synthetic resin fibers. Therefore, in cases where inorganic fibers and organic fibers cannot be treated separately, as in producing a filter of nonwoven fabric by entangling glass fibers and synthetic resin fibers, it is advisable to treat the fibers as the base, that is, to perform the step of forming the base protective layer on the fibers, and then form the fibers into nonwoven fabric. Alternatively, however, after a nonwoven fabric is formed, it may be subjected in its entirety to the step of forming the base protective layer.
- the photocatalytic semiconductor to be used may be TiO 2 , ZnO, SrTiO 3 , CdS, CdO, CaP, InP, In 2 O 3 , CaAs, BaTiO 3 , K 2 NbO 3 , Fe 2 O 3 , Ta 2 O 5 , WO 3 , SaO 2 , Bi 2 O 3 , NiO, Cu 2 O, SiC, SiO 2 , MoS 2 , MoS 3 , InPb, RuO 2 , or CeO 2 .
- photocatalytic semiconductors absorb ultraviolet radiation with a wavelength of 50 to 400 nm, which is slightly shorter than that of visible light. Some of the photocatalytic semiconductors, however, have an absorption wavelength falling within the range of visible light. For example, SiC has an absorption wavelength of 413 nm, CdS has an absorption wavelength of 496 nm, and Fe 2 O 3 has an absorption wavelength of 539 nm.
- the wavelength of light with which photocatalytic semiconductors are excited varies depending on their type, and therefore, a suitable photocatalytic semiconductor may be selected in accordance with the intended use or the emission spectrum characteristic of the source of ultraviolet radiation, or multiple types of photocatalytic semiconductors may be used in combination for adjustment.
- an inorganic pigment or a metal to thereby adjust the composition or by controlling the heating step in the production process, it is possible to shift the wavelength of ultraviolet radiation (absorption band) that is required to provide the photocatalytic function. For example, if a small quantity of CrO 3 is added to TiO 2 , then the absorption band shifts toward a longer wavelength side.
- Pt As an additive for providing a complementary function such as mildew resistance, sterilization, etc., Pt, Ag, Rh, RuO 2 , Nb, Cu, Sn, NiO and the like may be used in combination.
- TiO 2 titanium oxide
- ST-01 trade name; manufactured by Ishihara Sangyo Kaisha, Ltd.
- TO SOL trade name; manufactured by Tanaka Transfer Printing Co., Ltd.
- STS-01 trade name; manufactured by Ishihara Sangyo Kaisha, Ltd.
- TiO 2 constituting the powder or sol has a very small particle diameter of 7 to 20 nm.
- the base with the photocatalytic semiconductor thereon is subjected to heat treatment.
- the temperature for the fixing ranges relatively wide from 50 to 500°C, but in the case of using peroxotitanic acid as the base protective layer, the fixing is performed at a temperature of 200°C or less.
- rayon, acetate, nylon and polyester have heat resisting temperatures of 260°C or less, 200°C or less, 180°C or less, and 230°C or less, respectively, and thus can sufficiently withstand coating with heat applied thereto.
- the photocatalytic sheet produced in this manner as ultraviolet rays from fluorescent lamps in the room or ultraviolet rays in the sunlight are received, the photocatalytic semiconductor retained on the sheet is excited and decomposes harmful organic matter by means of oxidation-reduction, thus providing a deodorizing effect, an air purifying effect, a sterilizing effect, etc.
- the sheet is used as a curtain which is arranged at an opening and is liable to receive the sunlight
- the air in the room which rises and circulates within the room as it is heated, efficiently comes into contact with the photocatalytic semiconductor, whereby odor in the room and volatile organic compounds (VOC) contained in building materials, adhesives, etc. can be removed.
- VOC volatile organic compounds
- the sheet is used for medical articles such as sterilizing gauze or is used for sanitary articles such as moistened tissue, infections can be effectively prevented.
- the base may retain also an ultraviolet radiating material.
- photocatalytic sheet having an ultraviolet radiating material mixed in the base
- ultraviolet rays necessary for exciting the photocatalytic semiconductor are supplied by the photocatalytic sheet per se, so that the photocatalytic function can be obtained and maintained even while no or only little ultraviolet radiation is available from outside, such as in the nighttime or within doors.
- Ultraviolet radiating materials include a spontaneous emission type and a light storage type.
- the spontaneous emission-type ultraviolet radiating material is a material that consumes its internal energy to emit light by itself and utilizes radioactive decay of radium or promethium, and an emission spectrum thereof includes an ultraviolet region.
- a lump obtained by solidifying refined powder of rocks containing such a material is again crushed and the thus-obtained crushed particles are used.
- the particle diameter is 20 to 50 ⁇ m.
- the light storage-type ultraviolet radiating material is a material that obtains energy from outside and emits light by releasing the energy stored therein, and an emission spectrum thereof includes an ultraviolet region.
- a material “LUMINOVA” (trade name; manufactured by Nemoto & Company Ltd.) and “KEPRUS” (trade name; manufactured by Next Eye Co., Ltd.) are commercially available.
- These products contain strontium aluminate (SrAl 2 O 4 ) as a main component, besides high-purity alumina, strontium carbonate, europium, dysprosium, etc.
- the light storage-type ultraviolet radiating material is exposed to sufficiently intense ultraviolet rays from outside for 4 to 30 minutes, absorption of external energy for light emission becomes saturated, and even if the supply of external energy is cut off thereafter, the material keeps emitting light for about 1000 minutes, thus irradiating the photocatalytic semiconductor with ultraviolet rays.
- the spectrum of emitted ultraviolet rays has a wavelength peak in the vicinity of 440 to 530 nm, but includes also a wavelength region in which ordinary photocatalytic semiconductors are excited.
- Some of the ultraviolet radiating materials greatly lower in capacity on absorbing moisture; therefore, they are preferably mixed beforehand in the base so that they may not come into direct contact with moisture, on condition that the base has transparency to ultraviolet radiation.
- synthetic resin admixed with the ultraviolet radiating material is sprayed on the base for coating before the base protective layer is formed.
- the ultraviolet radiating material is retained on the sheet chiefly by means of adhesion or fixing to the surface of the base, but in the case of synthetic resin fibers or a synthetic resin film, the ultraviolet radiating material may be mixed in the base. Also, where the fibers used are synthetic resin filaments, the ultraviolet radiating material may be mixed in some of radially segmented regions as viewed in section, or be mixed in ring form so as to constitute the outermost layer as viewed in section.
- Such filaments are produced by extruding a raw resin mixed with the ultraviolet radiating material and a raw resin having no ultraviolet radiating material mixed therein from separate nozzles into the air or a cooling liquid such as organic solvent, water or the like, and bringing the extruded resins into close contact with each other before they set.
- the base is subject to photocatalytic deterioration caused due to the photocatalytic function of the photocatalytic semiconductor as well as to photochemical deterioration caused by ultraviolet rays, as mentioned above. Suppression of the photocatalytic deterioration is already stated above.
- the photochemical deterioration is suppressed by utilizing the fact that resins are different from one another as to the rate of photochemical deterioration and the wavelength with which they are most liable to be deteriorated.
- the wavelength that causes the greatest deterioration is 318 nm for polyester, 300 nm for polypropylene, 285 to 305 nm and 330 to 360 nm for polycarbonate, and 300 nm for polyethylene.
- an ultraviolet radiating material is selected of which the peak of emission wavelength spectrum differs from the wavelength that causes the greatest deterioration of the resin used. Also, the excitation wavelength of the photocatalytic semiconductor retained on the base is made different from the wavelength which causes the greatest deterioration of the synthetic resin. Needless to say, the addition of an ultraviolet ray absorbing material, such as 2-hydroxybenzophene or triazole, to the base is effective in preventing the photochemical deterioration.
- a base a nonwoven fabric (4880C, from Shinwa Co. Ltd.) obtained by bonding polyester fibers and rayon fibers together by an acrylic binder
- the base was first washed in tap water and then in pure water, and was dried at 70°C.
- the base was dipped into a sol of titanium peroxide (viscous sol containing 0.3 wt% TiO 3 and having pH 5) at room temperature (23.8°C), and after surplus sol was removed, the base was placed in a space in which titanium oxide powder (ST-01, from Ishihara Sangyo Kaisha, Ltd.) was floating, to allow titanium oxide particles to adhere to the entire surface of the base, followed by drying.
- titanium oxide powder ST-01, from Ishihara Sangyo Kaisha, Ltd.
- the base obtained in this manner was then half-dried in an atmosphere of 50°C, and the entire surface thereof was ironed at 120 to 150°C to fix the titanium oxide particles, thereby obtaining a final product.
- FIG. 1 is a schematic enlarged sectional view of a fiber constituting the fabric.
- the base protective layer 2 constituted by a layer of noncrystalline titanium peroxide particles is formed on the surface of the fiber 1 located at the center, and the photocatalytic semiconductor layer 3 is formed on the surface of the base protective layer 2.
- the final product was placed like wallpaper in the space of an ordinary room, and after the product was left to stand for two months, the product was pulled lengthwise and widthwise and was bent, but no abnormality was found as to strength and other properties.
- This experiment is being continued on a long-term basis, to observe deterioration of the base (photocatalytic deterioration and photochemical deterioration).
- a woven fabric (DEOLIA; from Nippon Fisba K. K.) made of mixed fibers containing 50% cotton and 50% polyester
- the base was first washed in tap water and then in pure water, and was dried at 70°C, as in Example 1. Subsequently, the base was dipped into a sol of titanium peroxide (sol containing 0.5 wt% TiO 3 and having pH 6.4) at room temperature (23.8°C), and after surplus sol was removed, the base was placed in a space in which titanium oxide powder (ST-01; from Ishihara Sangyo Kaisha, Ltd.) was floating, to allow titanium oxide particles to adhere to the entire surface of the woven fabric, followed by drying.
- a sol of titanium peroxide sol containing 0.5 wt% TiO 3 and having pH 6.4
- the base obtained in this manner was then half-dried in an atmosphere of 50°C, and the entire surface thereof was ironed at 120 to 150°C to fix the titanium oxide particles, thereby obtaining a final product.
- Each fiber had a cross section similar to that shown in the schematic diagram of FIG. 1.
- the final product was light yellowish white in color as a whole, and the external appearance thereof looked almost the same as that before the treatment.
- the final product was placed like wallpaper in the space of an ordinary room, and after the product was left to stand for two months, the product was pulled lengthwise and widthwise and was bent, but no abnormality was found as to strength and other properties. This experiment is being continued on a long-term basis, to observe deterioration of the base (photocatalytic deterioration and photochemical deterioration).
- the base was first washed in tap water and then in pure water, and was dried at 70°C, as in Example 1. Subsequently, the base was dipped into a mixture of a sol of titanium peroxide (sol containing 1.76 wt% TiO 3 and having pH 6.0) and a sol of titanium oxide (TO from Tanaka Transfer Printing Co., Ltd.; 3.94 wt% titanium oxide; pH 8.1) at room temperature (23.8°C). After surplus sol was removed, the base was dried in an atmosphere of 50°C.
- a sol of titanium peroxide sol containing 1.76 wt% TiO 3 and having pH 6.0
- a sol of titanium oxide TO from Tanaka Transfer Printing Co., Ltd.; 3.94 wt% titanium oxide; pH 8.1
- a layer constituted by a mixture of titanium peroxide particles and titanium oxide particles is formed on the surface of each fiber; since the sol of titanium peroxide has more excellent spreadability with respect to the surface of the fiber, a layer of titanium peroxide particles is formed near the surface of the fiber while a layer of titanium oxide is formed on the outermost side.
- the available photocatalytic capacity is somewhat low, it is unnecessary to perform an additional step for the adhesion of titanium oxide powder.
- the entire surface of the base was ironed at 120 to 150°C to fix the layer of titanium oxide particles and titanium peroxide particles, thereby obtaining a final product.
- the external appearance of the final product was almost the same as that before the treatment.
- the final product was placed like wallpaper in the space of an ordinary room, and after the product was left to stand for two months, the product was pulled lengthwise and widthwise and was bent, but no abnormality was found as to strength and other properties. This experiment is still being continued to observe deterioration of the base (photocatalytic deterioration and photochemical deterioration) on a long-term basis.
- FIGS. 2 to 4 each show an example wherein "LUMINOVA" as the light storage-type ultraviolet radiating material is mixed in a polyester fiber 1, in accordance with Examples 1 to 3 described above.
- the ultraviolet radiating material is mixed in the whole of the fiber 1, in the example of FIG. 3, the ultraviolet radiating material is mixed in a plurality of radially segmented regions of the fiber as viewed in section, and in the example of FIG. 4, the ultraviolet radiating material is mixed in ring form 1a to constitute the outermost layer of the fiber as viewed in section.
- hatching represents regions in which the ultraviolet radiating material is mixed
- reference numeral 1 denotes the fiber
- 2 denotes the base protective layer
- 3 denotes the layer of photocatalytic semiconductor particles.
- the peak wavelength of light that the polyester fiber absorbs is at 318 nm, and accordingly, the peak wavelength of light that the layer of titanium oxide particles absorbs is adjusted to 480 nm.
- the wavelength band of light that "LUMINOVA" radiates is, on the other hand, adjusted to 440 to 530 nm.
- FIG. 5 is a sectional view of a twisted yarn constituted by natural fibers and synthetic resin fibers admixed with the ultraviolet radiating material, and illustrates a means of imparting light storage capacity to a woven fabric using natural fibers.
- the large vessel 4 was placed on a desk, and the black-light lamps 5 were horizontally arranged immediately above the vessel at a distance of 70 mm from the top face of the desk.
- the six small vessels 6 were arranged inside the large vessel 4 at regular intervals, and the sheets 7 prepared as mentioned above were placed in the respective small vessels. Then, 50 cc of the colored water was poured into each of the small vessels 6. With the large vessel 4 closed with the cover, the vessels and the sheets were left to stand at room temperature, and change in color of the colored water in the individual small vessels was observed from outside.
- POLUX BLUE is a pigment of polymeric organic compound and is decomposed by the photocatalytic function of the photocatalytic semiconductor, so that it loses the function of coloring the solution. It is therefore possible to know the degree of progress of the oxidation-reduction caused by the photocatalytic function as well as the strength of the photocatalytic function.
- the protective layer constituted by noncrystalline titanium peroxide particles or inactivated titanium oxide particles is formed on the surface of the base. Accordingly, even if a photocatalytic semiconductor layer is formed on the surface of a base of natural fibers or synthetic resin fibers containing polymeric organic compound, the base is not decomposed by the photocatalytic function of the photocatalytic semiconductor, and thus is not deteriorated. Consequently, the sheet can be used for a long term as a photocatalytic sheet.
- the function of the photocatalytic sheet can be obtained even in a dark place where no ultraviolet rays reach. This capacity is useful when the sheet is used in filters or medical articles which are normally used at locations where ultraviolet rays are unlikely to reach. Also, since ultraviolet rays do not deteriorate the base containing polymeric organic compound, the photocatalytic sheet is improved in durability.
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Abstract
A photocatalytic sheet which has a base made of polymeric organic
compound, that is not decomposed by a photocatalytic function, and also
hardly loses the photocatalytic function after washing and is capable of
providing the photocatalytic function even in an environment without
sufficient ultraviolet radiation from outside. Using a fiber, a filament, a
yarn made of fibers or filaments, a ribbon, a knitted fabric, a woven
fabric, a nonwoven fabric, a film, etc. as the base, a base protective layer
is formed on a part of the base, which is made of the polymeric organic
compound, and a photocatalytic semiconductor layer is formed on the
entire surface of the base including the base protective layer.
Description
The present invention relates to a sheet of knitted fabric, woven
fabric, nonwoven fabric, etc., which is capable of decomposing harmful
organic compounds in gas or liquid by a photocatalytic function of metal
oxide, and thereby rendering the gas or liquid harmless or sterilizing the
same.
Many of metal oxides such as titanium oxide (TiO2) are called
optical semiconductors since electrons on their surface are made movable
relatively freely when they are excited by ultraviolet rays. The optical
semiconductor has a photocatalytic function of oxidizing or deoxidizing a
substance in contact with a surface of the semiconductor by the electrons
which are rendered freely movable by the excitation.
The photocatalytic function is utilized in a daily life to attain an
effect of deodorization or sterilization. For example, in order to purify
the air in a room of a house or facilities open to general public such as
hotels, public buildings and hospitals, the photocatalytic function is given
to materials of interiors including ceilings and walls, or the photocatalytic
semiconductor is retained in curtains which are often exposed to
ultraviolet radiation of the sunlight. Thus, the air which rises to circulate
in the room as being heated by the sunlight comes into contact with
sheets of these materials, so that odors in the room and volatile organic
compounds (VOC) contained in adhesives in backings of the interior
materials are effectively removed.
The woven fabrics for the interior materials and the curtains, as
well as filters in various devices, medical gauze, moistened tissue and
nonwoven fabrics such as artificial leather have a large number of gaps
between their fibers and thus are multi-surface objects, and hygienic,
medical or deodorizing effect can advantageously be obtained by
imparting the photocatalytic function to these objects.
These advantageous effects can be achieved on condition that the
fiber or fabric itself, which is a base for retaining the photocatalytic
semiconductor, should not be decomposed by the photocatalytic function.
However, the photocatalytic function is originally a function of
decomposing the polymeric organic compounds by the
oxidization/deoxidization action of the photocatalytic semiconductor
which is excited by irradiation of ultraviolet rays. Therefore, no problem
arises if the base retaining the photocatalytic semiconductor is made of
an inorganic material such as metallic fibers or glass fibers, but in the
case where the base is made of fibers of polymeric organic compound
such as natural fibers or synthetic resin fibers, the base itself is
decomposed and deteriorated with lapse of time (deterioration by
photocatalysis).
Further, polymeric organic compounds are decomposed and
deteriorated also by ultraviolet rays (photochemical deterioration). Most
part of external ultraviolet rays falling on the base having the
photocatalytic semiconductor layer on the surface thereof are absorbed at
the photocatalytic semiconductor layer, but the remaining part reaches
the base.
As a conventional sheet having the photocatalytic function, there is
known a sheet in which particles of white pigment, each retaining
particles of photocatalytic semiconductor on its surface, are contained or
filled in an air-permeable sheet as proposed in Japanese Laid-Open
Patent Publication No. 7-299354. However, this sheet with a unique
structure lacks versatility and it is not possible to make a soft material
such as gauze by using the sheet.
Japanese Laid-Open Patent Publication No. 7-316342 discloses
that synthetic resin containing particles of photocatalytic semiconductor
is formed into a sheet for wall materials, floor materials, and various
bags. However, when the photocatalytic semiconductor particles are
thus kneaded into the base, the photocatalytic function cannot be fully
achieved. Also, the technique disclosed in this publication cannot be
applied to fabric made of natural fibers which cannot be kneaded.
Further, Japanese Laid-Open Patent Publication No. 8-1010
discloses an adhesive sheet having a layer of fine particles of oxide
semiconductor on one surface thereof, an adhesive layer as an
intermediate layer, and a separating layer on the other surface thereof.
This sheet is intended to use at locations where it is difficult to fix
photocatalytic semiconductor particles, such as walls or ceilings, and
also cannot be applied to soil material such as gauze.
In the conventional sheets of these types, no consideration is given
to prevention or suppression of the deterioration by photocatalysis and
the photochemical deterioration. Also, the washability of the sheet for
reuse and the use of the sheet in an environment without sufficient
ultraviolet radiation, such as in the nighttime or in a dark room, are not
taken into account.
An object of the present invention is providing a photocatalytic
sheet which has a base, made of polymeric organic compound and
retaining photocatalytic semiconductor, that is not decomposed by a
photocatalytic function, and thus can withstand long-term use. The
object includes providing a photocatalytic sheet which hardly loses the
photocatalytic function even if washed, and is capable of providing the
photocatalytic function even in an environment without sufficient
ultraviolet radiation from outside.
A photocatalytic sheet according to the present invention
comprises a base having a part made of polymeric organic compound; a
base protective layer formed on a surface of the part made of polymeric
organic compound in the base, for intercepting photocatalytic function;
and a photocatalytic semiconductor layer formed on an entire surface of
the base including said base protective layer.
The base includes a fiber, a filament, a yarn made of fibers or
filaments, a ribbon, a knitted fabric, a woven fabric, a nonwoven fabric,
and a film made of synthetic resin.
The base protective layer may comprise noncrystalline titanium
peroxide particles or titanium oxide particles inactivated with respect to
photocatalytic function. The photocatalytic semiconductor layer may
comprise constituted by titanium oxide particles.
The base may retain a spontaneous emission-type ultraviolet
radiating material or a light storage-type ultraviolet radiating material. In
this case, the compositions of the ultraviolet radiating material and the
photocatalytic semiconductor layer are adjusted so that a peak region of
wavelength spectrum of light radiated from the ultraviolet radiating
material is shifted from a peak region of wavelength spectrum of light to
be absorbed by the polymeric organic compound, and overlaps at least in
part with a peak region of light absorption spectrum of the photocatalytic
semiconductor layer.
A photocatalytic sheet according to the present invention may take
the form of a knitted fabric, a woven fabric, a nonwoven fabric, or a film.
The material of the sheet may be natural fibers such as hemp, cotton and
wool, and also synthetic fibers (including filaments) or synthetic resin of
polyester, rayon, nylon, polypropylene, vinyl, acetate, acrylic, etc. The
sheet except the film is formed through the steps of fibers, spun yarns,
twisted yarns, or ribbons.
Also, metallic fibers or glass fibers may be used, and a single sheet
may be formed using a plurality of materials. Depending on the use of
the sheet, moreover, paper or artificial leather may be used. The sheet
needs to have a decorative element and sufficient strength when used for
the purposes of interior materials or accessories, and needs to have
flexibility for clothing or hygienic purposes.
A base protective layer is constituted by a layer of noncrystalline
titanium peroxide particles formed using an aqueous solution of titanium
peroxide, a peroxotitanic acid, a peroxotitanic acid containing an oxide
of metal other than titanium, etc., or by a layer of titanium oxide particles
inactivated in respect of photocatalytic function. The layer obtained in
this manner has no photocatalytic function and thus does not decompose
the base.
The layer of noncrystalline titanium peroxide particles can be
formed on the surface of the base in the following manner, for example.
A fabric as the base which has been subjected to dyeing as a final
step is sprayed with or dipped into an aqueous solution of titanium
peroxide showing an intermediate property between sol and gel states,
and after surplus solution is removed, the fabric is dried and then heated
so as to fix the titanium peroxide at a temperature of 200°C or less,
taking the heat resisting temperature of the base into consideration.
The surface of the base may alternatively be coated with an
aqueous solution of peroxotitanic acid by, for example, dipping as in the
aforementioned manner, dried and then heated for fixing at a temperature
of 200°C or less.
In this manner, a layer of noncrystalline titanium peroxide particles
is formed on the surface of the base.
In the case of using peroxotitanic acid, if the heating temperature is
higher than 200°C, the resultant noncrystalline titanium peroxide
particles show a property similar to that of titanium oxide of anatase type
and have a photocatalytic function.
As an alternative method, a raw resin for forming fibers as the base
may be ejected from a nozzle into an aqueous solution of peroxotitanic
acid so that a thin film of noncrystalline titanium peroxide particles may
be formed on the surface of each fiber. Also in this case, the fibers are
dried and then heated so as to fix the titanium peroxide at a temperature
of 200°C or less. The fixing may be performed after spinning, after
twisting, or after weaving.
The layer of titanium oxide inactivated in respect of the
photocatalytic function may be formed on the surface of the base in the
following manner, for example.
An ionic surface-active agent is mixed in a sol of titanium oxide of
anatase type such that the surface-active agent accounts for 1 wt% or
more with respect to the concentration of the titanium oxide (TiO2) in the
sol, thereby inactivating the photocatalytic function of the titanium oxide,
and then the base is sprayed with, dipped into, or applied with the sol.
Subsequently, the base is dried and then heated for fixing the titanium
oxide.
A photocatalytic semiconductor layer is formed on the surface of
the base treated in this manner, and in this case, even if the
photocatalytic semiconductor is excited upon exposure to ultraviolet
radiation, electrons moving toward the surface of the base combine with
ions of the ionic surface-active agent contained in the base protective
layer, thus preventing oxidation-reduction of the surface of the base.
Consequently, the base is not affected by the photocatalytic function and
thus can be protected.
The base on which the photocatalytic semiconductor is to be
retained is not limited to the form of knitted fabric, woven fabric,
nonwoven fabric or film, but may be of various forms obtained in
respective steps of the sheet production process, such as fibers, spun
yarns, twisted yarns, or ribbons. Particles of photocatalytic
semiconductor may be affixed at early stages of the process to fibers or
yarns, for example, on condition that no difficulty arises in performing
the treatment, in which case the photocatalytic semiconductor is firmly
fixed to the resultant sheet and the photocatalytic function can be
retained even if the sheet is washed several times.
Namely, as the base retaining photocatalytic semiconductor for
imparting the photocatalytic function to the sheet, one or some of the
forms including fiber, filament, yarn, ribbon, knitted fabric, woven fabric,
nonwoven fabric and film may be selected depending on the purpose.
The layer of noncrystalline titanium peroxide particles or the layer
of inactivated titanium oxide needs to be formed on natural fibers or
synthetic resin fibers. Therefore, in cases where inorganic fibers and
organic fibers cannot be treated separately, as in producing a filter of
nonwoven fabric by entangling glass fibers and synthetic resin fibers, it is
advisable to treat the fibers as the base, that is, to perform the step of
forming the base protective layer on the fibers, and then form the fibers
into nonwoven fabric. Alternatively, however, after a nonwoven fabric is
formed, it may be subjected in its entirety to the step of forming the base
protective layer.
The photocatalytic semiconductor to be used may be TiO2, ZnO,
SrTiO3, CdS, CdO, CaP, InP, In2O3, CaAs, BaTiO3, K2NbO3, Fe2O3, Ta2O5,
WO3, SaO2, Bi2O3, NiO, Cu2O, SiC, SiO2, MoS2, MoS3, InPb, RuO2, or
CeO2.
These photocatalytic semiconductors absorb ultraviolet radiation
with a wavelength of 50 to 400 nm, which is slightly shorter than that of
visible light. Some of the photocatalytic semiconductors, however, have
an absorption wavelength falling within the range of visible light. For
example, SiC has an absorption wavelength of 413 nm, CdS has an
absorption wavelength of 496 nm, and Fe2O3 has an absorption
wavelength of 539 nm.
Thus, the wavelength of light with which photocatalytic
semiconductors are excited varies depending on their type, and therefore,
a suitable photocatalytic semiconductor may be selected in accordance
with the intended use or the emission spectrum characteristic of the
source of ultraviolet radiation, or multiple types of photocatalytic
semiconductors may be used in combination for adjustment.
Also, by adding an inorganic pigment or a metal to thereby adjust
the composition or by controlling the heating step in the production
process, it is possible to shift the wavelength of ultraviolet radiation
(absorption band) that is required to provide the photocatalytic function.
For example, if a small quantity of CrO3 is added to TiO2, then the
absorption band shifts toward a longer wavelength side.
As an additive for providing a complementary function such as
mildew resistance, sterilization, etc., Pt, Ag, Rh, RuO2, Nb, Cu, Sn, NiO
and the like may be used in combination.
Among the photocatalytic semiconductors mentioned above, TiO2
(titanium oxide) is commercially available, harmless to the human body,
inexpensive, and easy to use. "ST-01" (trade name; manufactured by
Ishihara Sangyo Kaisha, Ltd.) is supplied in the form of powder, while
"TO SOL" (trade name; manufactured by Tanaka Transfer Printing Co.,
Ltd.) and "STS-01" (trade name; manufactured by Ishihara Sangyo
Kaisha, Ltd.) are supplied in the form of sol. TiO2 constituting the
powder or sol has a very small particle diameter of 7 to 20 nm.
To fix the photocatalytic semiconductor on the base, various means
such as spraying, applying, dipping or sputtering can be employed, and a
suitable means may be selected depending on the base type. However,
since the sheet to be obtained is required to withstand reuse or washing,
the base with the photocatalytic semiconductor thereon is subjected to
heat treatment. In the case of TiO2, the temperature for the fixing ranges
relatively wide from 50 to 500°C, but in the case of using peroxotitanic
acid as the base protective layer, the fixing is performed at a temperature
of 200°C or less. As regards the heat resistance of fibers presently on
the market, rayon, acetate, nylon and polyester have heat resisting
temperatures of 260°C or less, 200°C or less, 180°C or less, and 230°C
or less, respectively, and thus can sufficiently withstand coating with
heat applied thereto.
With the photocatalytic sheet produced in this manner, as
ultraviolet rays from fluorescent lamps in the room or ultraviolet rays in
the sunlight are received, the photocatalytic semiconductor retained on
the sheet is excited and decomposes harmful organic matter by means of
oxidation-reduction, thus providing a deodorizing effect, an air purifying
effect, a sterilizing effect, etc.
Especially in the case where the sheet is used as a curtain which is
arranged at an opening and is liable to receive the sunlight, the air in the
room, which rises and circulates within the room as it is heated,
efficiently comes into contact with the photocatalytic semiconductor,
whereby odor in the room and volatile organic compounds (VOC)
contained in building materials, adhesives, etc. can be removed.
Also, where the sheet is used for medical articles such as
sterilizing gauze or is used for sanitary articles such as moistened tissue,
infections can be effectively prevented.
The base may retain also an ultraviolet radiating material.
With a photocatalytic sheet having an ultraviolet radiating material
mixed in the base, ultraviolet rays necessary for exciting the
photocatalytic semiconductor are supplied by the photocatalytic sheet per
se, so that the photocatalytic function can be obtained and maintained
even while no or only little ultraviolet radiation is available from outside,
such as in the nighttime or within doors.
Ultraviolet radiating materials include a spontaneous emission type
and a light storage type. The spontaneous emission-type ultraviolet
radiating material (spontaneous emission-type luminous ceramic) is a
material that consumes its internal energy to emit light by itself and
utilizes radioactive decay of radium or promethium, and an emission
spectrum thereof includes an ultraviolet region. Presently, a lump
obtained by solidifying refined powder of rocks containing such a
material is again crushed and the thus-obtained crushed particles are
used. The particle diameter is 20 to 50 µm.
The light storage-type ultraviolet radiating material (light storage-type
luminous ceramic) is a material that obtains energy from outside and
emits light by releasing the energy stored therein, and an emission
spectrum thereof includes an ultraviolet region. As such a material,
"LUMINOVA" (trade name; manufactured by Nemoto & Company Ltd.)
and "KEPRUS" (trade name; manufactured by Next Eye Co., Ltd.) are
commercially available. These products contain strontium aluminate
(SrAl2O4) as a main component, besides high-purity alumina, strontium
carbonate, europium, dysprosium, etc.
If the light storage-type ultraviolet radiating material is exposed to
sufficiently intense ultraviolet rays from outside for 4 to 30 minutes,
absorption of external energy for light emission becomes saturated, and
even if the supply of external energy is cut off thereafter, the material
keeps emitting light for about 1000 minutes, thus irradiating the
photocatalytic semiconductor with ultraviolet rays. In the case of
"LUMINOVA," for example, the spectrum of emitted ultraviolet rays has
a wavelength peak in the vicinity of 440 to 530 nm, but includes also a
wavelength region in which ordinary photocatalytic semiconductors are
excited.
Some of the ultraviolet radiating materials greatly lower in capacity
on absorbing moisture; therefore, they are preferably mixed beforehand
in the base so that they may not come into direct contact with moisture,
on condition that the base has transparency to ultraviolet radiation. In
the case where natural fibers are used, synthetic resin admixed with the
ultraviolet radiating material is sprayed on the base for coating before the
base protective layer is formed.
The ultraviolet radiating material is retained on the sheet chiefly by
means of adhesion or fixing to the surface of the base, but in the case of
synthetic resin fibers or a synthetic resin film, the ultraviolet radiating
material may be mixed in the base. Also, where the fibers used are
synthetic resin filaments, the ultraviolet radiating material may be mixed
in some of radially segmented regions as viewed in section, or be mixed
in ring form so as to constitute the outermost layer as viewed in section.
Such filaments are produced by extruding a raw resin mixed with
the ultraviolet radiating material and a raw resin having no ultraviolet
radiating material mixed therein from separate nozzles into the air or a
cooling liquid such as organic solvent, water or the like, and bringing the
extruded resins into close contact with each other before they set.
In the case of natural fibers, particles of the ultraviolet radiating
material cannot be mixed in the fibers themselves; therefore, in the step
of twisting yarns, the natural fibers and synthetic resin fibers admixed
with the ultraviolet radiating material are twisted together.
The base is subject to photocatalytic deterioration caused due to
the photocatalytic function of the photocatalytic semiconductor as well as
to photochemical deterioration caused by ultraviolet rays, as mentioned
above. Suppression of the photocatalytic deterioration is already stated
above.
The photochemical deterioration is suppressed by utilizing the fact
that resins are different from one another as to the rate of photochemical
deterioration and the wavelength with which they are most liable to be
deteriorated. In typical synthetic resins, the wavelength that causes the
greatest deterioration is 318 nm for polyester, 300 nm for polypropylene,
285 to 305 nm and 330 to 360 nm for polycarbonate, and 300 nm for
polyethylene.
Namely, to prevent the photochemical deterioration, an ultraviolet
radiating material is selected of which the peak of emission wavelength
spectrum differs from the wavelength that causes the greatest
deterioration of the resin used. Also, the excitation wavelength of the
photocatalytic semiconductor retained on the base is made different from
the wavelength which causes the greatest deterioration of the synthetic
resin. Needless to say, the addition of an ultraviolet ray absorbing
material, such as 2-hydroxybenzophene or triazole, to the base is
effective in preventing the photochemical deterioration.
The photocatalytic sheet according to the present invention will be
now described with reference to specific examples.
Using, as a base, a nonwoven fabric (4880C, from Shinwa Co.
Ltd.) obtained by bonding polyester fibers and rayon fibers together by
an acrylic binder, the base was first washed in tap water and then in pure
water, and was dried at 70°C. Subsequently, the base was dipped into a
sol of titanium peroxide (viscous sol containing 0.3 wt% TiO3 and having
pH 5) at room temperature (23.8°C), and after surplus sol was removed,
the base was placed in a space in which titanium oxide powder (ST-01,
from Ishihara Sangyo Kaisha, Ltd.) was floating, to allow titanium oxide
particles to adhere to the entire surface of the base, followed by drying.
The base obtained in this manner was then half-dried in an
atmosphere of 50°C, and the entire surface thereof was ironed at 120 to
150°C to fix the titanium oxide particles, thereby obtaining a final
product.
The final product was light yellowish white in color as a whole,
and although the gaps between the fibers constituting the nonwoven
fabric were slightly clogged, the external appearance looked almost the
same as that before the treatment. FIG. 1 is a schematic enlarged
sectional view of a fiber constituting the fabric. As shown in the figure,
the base protective layer 2 constituted by a layer of noncrystalline
titanium peroxide particles is formed on the surface of the fiber 1 located
at the center, and the photocatalytic semiconductor layer 3 is formed on
the surface of the base protective layer 2.
The final product was placed like wallpaper in the space of an
ordinary room, and after the product was left to stand for two months, the
product was pulled lengthwise and widthwise and was bent, but no
abnormality was found as to strength and other properties. This
experiment is being continued on a long-term basis, to observe
deterioration of the base (photocatalytic deterioration and photochemical
deterioration).
The oxidation-reduction capacity is summarized hereinafter as
experimental results.
Using, as a base, a woven fabric (DEOLIA; from Nippon Fisba K.
K.) made of mixed fibers containing 50% cotton and 50% polyester, the
base was first washed in tap water and then in pure water, and was dried
at 70°C, as in Example 1. Subsequently, the base was dipped into a sol
of titanium peroxide (sol containing 0.5 wt% TiO3 and having pH 6.4) at
room temperature (23.8°C), and after surplus sol was removed, the base
was placed in a space in which titanium oxide powder (ST-01; from
Ishihara Sangyo Kaisha, Ltd.) was floating, to allow titanium oxide
particles to adhere to the entire surface of the woven fabric, followed by
drying.
The base obtained in this manner was then half-dried in an
atmosphere of 50°C, and the entire surface thereof was ironed at 120 to
150°C to fix the titanium oxide particles, thereby obtaining a final
product.
Each fiber had a cross section similar to that shown in the
schematic diagram of FIG. 1.
The final product was light yellowish white in color as a whole,
and the external appearance thereof looked almost the same as that
before the treatment. The final product was placed like wallpaper in the
space of an ordinary room, and after the product was left to stand for two
months, the product was pulled lengthwise and widthwise and was bent,
but no abnormality was found as to strength and other properties. This
experiment is being continued on a long-term basis, to observe
deterioration of the base (photocatalytic deterioration and photochemical
deterioration).
The oxidation-reduction capacity is summarized hereinafter as
experimental results.
Using a woven fabric (DUFY; from Nippon Fisba K. K.) of 100%
cotton as a base, the base was first washed in tap water and then in pure
water, and was dried at 70°C, as in Example 1. Subsequently, the base
was dipped into a mixture of a sol of titanium peroxide (sol containing
1.76 wt% TiO3 and having pH 6.0) and a sol of titanium oxide (TO from
Tanaka Transfer Printing Co., Ltd.; 3.94 wt% titanium oxide; pH 8.1) at
room temperature (23.8°C). After surplus sol was removed, the base
was dried in an atmosphere of 50°C.
In this case, a layer constituted by a mixture of titanium peroxide
particles and titanium oxide particles is formed on the surface of each
fiber; since the sol of titanium peroxide has more excellent spreadability
with respect to the surface of the fiber, a layer of titanium peroxide
particles is formed near the surface of the fiber while a layer of titanium
oxide is formed on the outermost side. Although the available
photocatalytic capacity is somewhat low, it is unnecessary to perform an
additional step for the adhesion of titanium oxide powder.
Subsequently, the entire surface of the base was ironed at 120 to
150°C to fix the layer of titanium oxide particles and titanium peroxide
particles, thereby obtaining a final product.
The external appearance of the final product was almost the same
as that before the treatment. The final product was placed like wallpaper
in the space of an ordinary room, and after the product was left to stand
for two months, the product was pulled lengthwise and widthwise and
was bent, but no abnormality was found as to strength and other
properties. This experiment is still being continued to observe
deterioration of the base (photocatalytic deterioration and photochemical
deterioration) on a long-term basis.
The oxidation-reduction capacity is summarized hereinafter as
experimental results.
FIGS. 2 to 4 each show an example wherein "LUMINOVA" as the
light storage-type ultraviolet radiating material is mixed in a polyester
fiber 1, in accordance with Examples 1 to 3 described above. In the
example of FIG. 2, the ultraviolet radiating material is mixed in the whole
of the fiber 1, in the example of FIG. 3, the ultraviolet radiating material
is mixed in a plurality of radially segmented regions of the fiber as
viewed in section, and in the example of FIG. 4, the ultraviolet radiating
material is mixed in ring form 1a to constitute the outermost layer of the
fiber as viewed in section. In the figures, hatching represents regions in
which the ultraviolet radiating material is mixed, reference numeral 1
denotes the fiber, 2 denotes the base protective layer, and 3 denotes the
layer of photocatalytic semiconductor particles.
The peak wavelength of light that the polyester fiber absorbs is at
318 nm, and accordingly, the peak wavelength of light that the layer of
titanium oxide particles absorbs is adjusted to 480 nm. The wavelength
band of light that "LUMINOVA" radiates is, on the other hand, adjusted
to 440 to 530 nm.
FIG. 5 is a sectional view of a twisted yarn constituted by natural
fibers and synthetic resin fibers admixed with the ultraviolet radiating
material, and illustrates a means of imparting light storage capacity to a
woven fabric using natural fibers.
The following describes the experimental results as to the effect of
the photocatalytic function observed when the photocatalytic sheets
obtained according to Examples 1 and 2 were irradiated with ultraviolet
rays.
As shown in FIGS. 6 and 7, the large vessel 4 was placed on a
desk, and the black-light lamps 5 were horizontally arranged immediately
above the vessel at a distance of 70 mm from the top face of the desk.
The six small vessels 6 were arranged inside the large vessel 4 at regular
intervals, and the sheets 7 prepared as mentioned above were placed in
the respective small vessels. Then, 50 cc of the colored water was
poured into each of the small vessels 6. With the large vessel 4 closed
with the cover, the vessels and the sheets were left to stand at room
temperature, and change in color of the colored water in the individual
small vessels was observed from outside.
POLUX BLUE is a pigment of polymeric organic compound and is
decomposed by the photocatalytic function of the photocatalytic
semiconductor, so that it loses the function of coloring the solution. It is
therefore possible to know the degree of progress of the oxidation-reduction
caused by the photocatalytic function as well as the strength of
the photocatalytic function.
Elapsed | Status | |
2 hours | No change was observed. | |
4 hours | Decomposition product of the coloring matter deposited on the bottom was observed, and the coloring of each small vessel was obviously lightened. | |
6 hours | No particular change was observed. | |
8 hours | The coloring of the small vessels in which Sheets a and b had been placed appeared to be slightly lighter than that of the other small vessels. | |
10 hours | The coloring of the small vessels in which Sheets a and b had been placed was obviously lighter than that of the other small vessels. The coloring of Specimens c and d was the second lightest. | |
24 hours | Almost no coloring was observed in respect of the liquid in the small vessels in which Sheets a and b had been placed. For Specimens a and b, all POLUX BLUE was judged to be decomposed, and thus decomposition was completed. For the other specimens, slight coloring was observed. The coloring of Specimen e was darker than that of Specimen f. | |
26 hours | The liquid in all small vessels became colorless. For all specimens, decomposition was completed. |
The sheets a to f used in the first testing were washed, and
experiment was conducted following the same procedure. In this case,
50 cc of POLUX BLUE colored liquid was poured afresh into each of the
small vessels.
Elapsed | Status | |
2 hours | Decomposition considerably advanced. For Specimens a, b and c, deposit was observed, revealing that the photocatalytic function was not deteriorated even after the washing. | |
21 hours | The liquid in all small vessels became colorless, and thus decomposition of POLUX BLUE was completed. |
The sheets b, e and f used in the second testing were again
washed, 50 cc of POLUX BLUE colored liquid was poured afresh into
each small vessel, and experiment was conducted again following the
same procedure. The small vessels contained in the large vessel were
three in number.
Elapsed | Status | |
2 hours | The degree of coloring of all small vessels was found to be small, but the change observed could not be called large. | |
6 hours | For all of the small vessels, the degree of coloring was considerably small. The advance of decomposition appeared to be the same for all specimens. | |
20 hours | For all of the small vessels, only slight coloring was observed. | |
24 hours | No coloring was observed in respect of all small vessels, and thus decomposition was completed. |
The foregoing reveals that, although the sheets have different
strengths of photocatalytic function, that is, (a, b) > (c, d) > f > e, they all
exhibit sufficient oxidation-reduction effect.
According to the present invention, the protective layer constituted
by noncrystalline titanium peroxide particles or inactivated titanium
oxide particles is formed on the surface of the base. Accordingly, even if
a photocatalytic semiconductor layer is formed on the surface of a base
of natural fibers or synthetic resin fibers containing polymeric organic
compound, the base is not decomposed by the photocatalytic function of
the photocatalytic semiconductor, and thus is not deteriorated.
Consequently, the sheet can be used for a long term as a photocatalytic
sheet.
In the case where the base is admixed with an ultraviolet radiating
material, moreover, the function of the photocatalytic sheet can be
obtained even in a dark place where no ultraviolet rays reach. This
capacity is useful when the sheet is used in filters or medical articles
which are normally used at locations where ultraviolet rays are unlikely
to reach. Also, since ultraviolet rays do not deteriorate the base
containing polymeric organic compound, the photocatalytic sheet is
improved in durability.
Claims (8)
- A photocatalytic sheet comprising:a base having a part made of polymeric organic compound;a base protective layer formed on a surface of said part made of polymeric organic compound in said base, for intercepting photocatalytic function; anda photocatalytic semiconductor layer formed on an entire surface of said base including said base protective layer.
- A photocatalytic sheet according to claim 1, said base including a fiber, a filament, a yarn made of fibers or filaments, a ribbon, a knitted fabric, a woven fabric, a nonwoven fabric, and a film made of synthetic resin.
- A photocatalytic sheet according to claim 1, said base protective layer comprising noncrystalline titanium peroxide particles.
- A photocatalytic sheet according to claim 1, said base protective layer comprising titanium oxide particles inactivated with respect to the photocatalytic function.
- A photocatalytic sheet according to any one of claims 1 through 4, said photocatalytic semiconductor layer comprising titanium oxide particles.
- A photocatalytic sheet according to any one of claims 1 through 4, said base retaining a spontaneous emission-type ultraviolet radiating material.
- A photocatalytic sheet according to any one of claims 1 through 4, said base retaining a light storage-type ultraviolet radiating material.
- The photocatalytic sheet according to claim 6 or 7, wherein respective compositions of said ultraviolet radiating material and said photocatalytic semiconductor layer are adjusted so that a peak region of wavelength spectrum of light radiated from said ultraviolet radiating material is shifted from a peak region of wavelength spectrum of light to be absorbed by said polymeric organic compound, and overlaps at least in part with a peak region of light absorption spectrum of said photocatalytic semiconductor layer.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP192807/96 | 1996-07-02 | ||
JP19280796A JP3786474B2 (en) | 1996-07-02 | 1996-07-02 | Photocatalyst sheet material |
PCT/JP1997/002242 WO1998000290A1 (en) | 1996-07-02 | 1997-06-27 | Photocatalyst sheet |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0876907A2 true EP0876907A2 (en) | 1998-11-11 |
Family
ID=16297323
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP97928504A Withdrawn EP0876907A2 (en) | 1996-07-02 | 1997-06-27 | Photocatalyst sheet |
Country Status (7)
Country | Link |
---|---|
US (1) | US6113861A (en) |
EP (1) | EP0876907A2 (en) |
JP (1) | JP3786474B2 (en) |
KR (1) | KR19990044159A (en) |
CA (1) | CA2230812A1 (en) |
TW (1) | TW390842B (en) |
WO (1) | WO1998000290A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1008565A1 (en) * | 1998-12-11 | 2000-06-14 | Choshu Iwashita | Process for the preparation of thread, string, rope or woven fabric with photocatalyst for decomposing organic compounds |
EP1067092A1 (en) * | 1999-07-05 | 2001-01-10 | Morioki Sangyo Company Limited | A method for preparing a composition for titanium peroxide film |
EP1555064A1 (en) * | 2004-01-19 | 2005-07-20 | Bellobono Innovative Technologies S.R.L. | Photocatalytic membrane, process for its production and use thereof |
US7786033B2 (en) * | 1998-06-10 | 2010-08-31 | Saint-Gobain Recherche | Substrate with a photocatalytic coating |
EP2595923A2 (en) * | 2010-07-23 | 2013-05-29 | UV Cleaning Systems, Inc. | Solar-activated photochemical purification of fluids |
US9017613B2 (en) | 2007-06-20 | 2015-04-28 | Uvcleaning Systems, Inc. | Ultraviolet photoreactor for the purification of fluids |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020081246A1 (en) * | 1997-08-25 | 2002-06-27 | Hoya Corporation | Photocatalytic filter |
JP2000119958A (en) * | 1998-10-15 | 2000-04-25 | Toray Ind Inc | Functional fiber structure |
JP2000189805A (en) * | 1998-12-25 | 2000-07-11 | Agency Of Ind Science & Technol | Photocatalyst compounded with luminous material |
JP2000328439A (en) * | 1999-05-19 | 2000-11-28 | Toray Ind Inc | Polyester fiber cloth |
JP2001220141A (en) * | 2000-02-03 | 2001-08-14 | Toho Titanium Co Ltd | Titanium oxide dispersion |
JP3513589B2 (en) * | 2000-03-24 | 2004-03-31 | 独立行政法人物質・材料研究機構 | Ultra thin titania film and method for producing the same |
US7521039B2 (en) * | 2002-11-08 | 2009-04-21 | Millennium Inorganic Chemicals, Inc. | Photocatalytic rutile titanium dioxide |
US6884752B2 (en) * | 2002-12-31 | 2005-04-26 | Prizmalite Industries, Inc. | Photocatalytically-active, self-cleaning aqueous coating compositions and methods |
KR100646421B1 (en) * | 2003-10-02 | 2006-11-17 | 윤영주 | A method for improvement of the surface of polymer film |
US7625835B2 (en) * | 2005-06-10 | 2009-12-01 | Gm Global Technology Operations, Inc. | Photocatalyst and use thereof |
US20070054072A1 (en) * | 2005-09-08 | 2007-03-08 | Lexmark International, Inc. | Packaging material for a developing agent cartridge |
US20070141319A1 (en) * | 2005-12-21 | 2007-06-21 | Shulong Li | Photocatalytic substrate and process for producing the same |
US8883115B2 (en) | 2006-01-12 | 2014-11-11 | University Of Arkansas Technology Development Foundation | TiO2 nanostructures, membranes and films, and methods of making same |
FR3113674A1 (en) * | 2020-08-27 | 2022-03-04 | Saint-Gobain Glass France | Laminated glazing having a layer of polyvinyl butyral in which is integrated a fabric comprising an ultraviolet ink |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04112822A (en) * | 1990-08-30 | 1992-04-14 | Takeda Chem Ind Ltd | Sheet material and product having hygienic and sanitary function produced by using the same |
AU676299B2 (en) * | 1993-06-28 | 1997-03-06 | Akira Fujishima | Photocatalyst composite and process for producing the same |
JPH07316342A (en) * | 1994-05-26 | 1995-12-05 | Goyo Paper Working Co Ltd | Synthetic resin composition containing photocatalyst and laminate containing the composition layer |
JPH08266902A (en) * | 1995-03-29 | 1996-10-15 | Mitsubishi Paper Mills Ltd | Environment purifying material using photocatalyst and its composition |
JPH0975633A (en) * | 1995-07-08 | 1997-03-25 | Toto Ltd | Filter product |
JPH0978454A (en) * | 1995-07-08 | 1997-03-25 | Toto Ltd | Sheet product for outdoor |
-
1996
- 1996-07-02 JP JP19280796A patent/JP3786474B2/en not_active Expired - Fee Related
-
1997
- 1997-06-27 KR KR1019980701393A patent/KR19990044159A/en not_active Application Discontinuation
- 1997-06-27 WO PCT/JP1997/002242 patent/WO1998000290A1/en not_active Application Discontinuation
- 1997-06-27 CA CA002230812A patent/CA2230812A1/en not_active Abandoned
- 1997-06-27 US US09/029,393 patent/US6113861A/en not_active Expired - Fee Related
- 1997-06-27 EP EP97928504A patent/EP0876907A2/en not_active Withdrawn
- 1997-07-02 TW TW086109303A patent/TW390842B/en not_active IP Right Cessation
Non-Patent Citations (1)
Title |
---|
See references of WO9800290A1 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7786033B2 (en) * | 1998-06-10 | 2010-08-31 | Saint-Gobain Recherche | Substrate with a photocatalytic coating |
EP1008565A1 (en) * | 1998-12-11 | 2000-06-14 | Choshu Iwashita | Process for the preparation of thread, string, rope or woven fabric with photocatalyst for decomposing organic compounds |
EP1067092A1 (en) * | 1999-07-05 | 2001-01-10 | Morioki Sangyo Company Limited | A method for preparing a composition for titanium peroxide film |
EP1555064A1 (en) * | 2004-01-19 | 2005-07-20 | Bellobono Innovative Technologies S.R.L. | Photocatalytic membrane, process for its production and use thereof |
US9017613B2 (en) | 2007-06-20 | 2015-04-28 | Uvcleaning Systems, Inc. | Ultraviolet photoreactor for the purification of fluids |
EP2595923A2 (en) * | 2010-07-23 | 2013-05-29 | UV Cleaning Systems, Inc. | Solar-activated photochemical purification of fluids |
EP2595923A4 (en) * | 2010-07-23 | 2014-01-22 | Uv Cleaning Systems Inc | Solar-activated photochemical purification of fluids |
AU2011280900B2 (en) * | 2010-07-23 | 2015-03-19 | Uvcleaning Systems, Inc. | Solar-activated photochemical purification of fluids |
Also Published As
Publication number | Publication date |
---|---|
JPH1016121A (en) | 1998-01-20 |
WO1998000290A1 (en) | 1998-01-08 |
KR19990044159A (en) | 1999-06-25 |
US6113861A (en) | 2000-09-05 |
JP3786474B2 (en) | 2006-06-14 |
TW390842B (en) | 2000-05-21 |
CA2230812A1 (en) | 1998-01-08 |
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